Answer:
sin 5x cos x - cos 5x sin x = sin(4x)
Explanation:
Given that the trigonometric expression,
sin 5x cos x - cos 5x sin x
Here we use the "sum and difference formulas"
Sum and Difference Formulas
sin(A+B)=sin A cos B + cos A sin B
sin(A-B)=sin A cos B - cos A sin B
cos(A+B)=cos A cos B - sin A sin B
cos(A-B)=cos A cos B + sin A sin B
So,
sin 5x cos x - cos 5x sin x = sin (5x - x)
sin 5x cos x - cos 5x sin x = sin(4x)
That's the final answer.